QUEKETT MICROSCOPICAL CLUB. dS 



greatest of all, their ready construction of any suitable form and 

 size for the requirements of a particular case. The only part 

 to wear out is the rubber ring, and that will last a considerable 

 time. Mr. Cook had frequently had a trough in use for many 

 weeks, containing organisms whose development he wished to 

 watch. Several members spoke in appreciation of the advan- 

 tages of the little apparatus, and a hearty vote of thanks was 

 passed to Mr. Cook for bringing it before the meeting. 



Mr. Burton then read a short paper, " Notes on the Aleurodes 

 Fly." The Cambridge Natural History definition of the family 

 is, " Minute insects with four mealy wings, seven-jointed antennae, 

 two-jointed feet, terminating in two claws and a third process." 

 Mr. Burton said the subject was not quite new to the members, 

 as Mr. R. T. Lewis, in 1895, described and figured a new species 

 that had been sent to him from Natal. It was named Aleurodes 

 asparagi, having been found on plants belonging to the genus 

 Asparagus in Natal. The paper was a most useful one, and 

 gave more detail than any other with which he was acquainted. 

 It will be found in the Quekett Microscopical Club Journal, vol. vi., 

 second series. 



Mr. R. T. Lewis said, with reference to the destruction of a 

 pest by the introduction of its enemies, a case in point occurred 

 in connection with the notorious Icerya purcJiasi, which, having 

 been introduced into South Africa, had affected the orange 

 and lemon trees over a district of 800 square miles. Laws were 

 passed requiring infected trees to be cut down and burnt ; but 

 the inhabitants, whilst they cut them down, dragged them through 

 the villages for firewood, and so distributed the insects still 

 further. The discovery of the male determined that it was 

 the Australian species which had been imported, and, finding 

 that in Australia the Icerya was kept down by a species of 

 Rodolia (one of the Lady- bird tribe), large numbers of these 

 insects were imported, and now the pest was reduced to manage- 

 able limits. 



A vote of thanks was passed by the members for Mr. Burton's 

 paper and interesting exhibits. 



At the 513th Ordinary Meeting, held on January 25th, 1916, the 

 President, Prof. Arthur Dendy, D.Sc, F.R.S., in the chair, the 



